Run rake task after capistrano deployment

systme_update_rules.rake

namespace :system do
  desc 'Update the system rules '
  task :update_rules do
    on roles(:all) do
      within release_path do
        with rails_env: fetch(:rails_env) do
          execute :rake, 'system:update_rules'
        end
      end
    end
  end
end

# credits:
# https://coderwall.com/p/doa0mq/running-a-rake-task-during-a-rails-4-deployment-using-capistrano-3